No description available.

No description available.

Call number: LD2668 .T4 1979 W33 / Master of Science

A simulation program to study the three dimensional temperature distributions produced by hyperthermia in anatomically realistic inhomogeneous tissue models has been developed. The anatomical data for the inhomogeneous tissues of the human body are entered on a digitizing tablet from serial CT scans. The program not only predicts temperature distributions in regions dominated by blood perfusion (with large number of small capillaries), but it can also predict the temperatures inside of and at the vicinity of large blood vessels. The program can be used for different power deposition patterns from various heating modalities, but they must be calculated independently. In this study, the author's attention has been focused on ferromagnetic implants. The program has been used to comparatively evaluate two and three dimensional simulations in a series of parametric calculations based on simple tissue models for both uniform power deposition and ferromagnetic implants. The conclusions drawn from these studies are that two dimensional simulations can lead to significant errors in many situations, and therefore three dimensional simulations will be necessary for accurate patient treatment planning. The conclusion from the geometrically simple model is substantiated by the results obtained using the full 3D model for actual patient anatomical simulations. The program has also been used for several parametric studies. The effect of the thermal conductivity used in the models on the temperature field has been studied, and the results show that its value in the range of 0.4 to 0.6 W/m/°C (valid for most soft tissues) has only a slight effect on the resultant temperature fields. The heating ability of the ferromagnetic implants has also been investigated for different blood perfusions. The effects of the Curie point of the ferromagnetic seeds, and seed spacing are also studied. Finally, the impact of large blood vessels on the resultant temperatures are studied, and the results show that the effect is dramatic and therefore it must be included in the simulations in order to predict accurate temperature fields. Finally, the program has been used to analyze a previously performed dog experiment, and a previously performed clinical treatment. A comparison between the predicted temperatures and the measured ones show that good agreement has been achieved for the clinical treatment, but not for the dog experiment. These results are studied in detail, and the conditions under which this program can be used as a hyperthermia patient treatment planning tool is discussed.

No description available.

The purpose of this study was to determine if mild heat stress induced by wearing a wet suit while swimming in relatively warm water (25.4 ± 0.1°C) increases the risk of heat injury during the subsequent cycling and running stages. Specificlly, during an Olympic distance triathlon in a hot and humid environment (32°C & 65% RH). Five male triathletes randomly completed two simulated triathlons (Swim=30 min; Bike=40 km; Run=10 km) in the laboratory using a swimming flume, cycle ergometer, and running treadmill. In both trials, all conditions were identical, except for the swimming portion in which a full length, sleeveless neoprene wet suit was worn during one trial (WS) and a competitive brief swimming suit during the other (SS). The swim portion consisted of a 30 min standardized swim in which oxygen consumption (V02) was replicated, regardless of WS or SS. During the cycling and running stages, however, the subjects were asked to complete the distances as fast as possible. Core Temperature (T) was not significantly different between the SS and WS trials at any time point during the triathlon. However, mean skin temperature (TSk) and mean body temperature (Tb) were higher (p<0.05) in the WS at 15 (TSk=+4.1°C, Tb=+1.5°C) and 30 min (TSk=+4°C, Tb=+1.6°C) of the swim. These TSk and Tb differences were eliminated by 15 min of the cycling stage and remained similar (p>0.05) through the end of the triathlon. Moreover, there were no differences (p>0.05) in V02, heart rate (HR), rating of perceived exertion (RPE), or thermal sensation (TS) between the WS and SS. Additionally, no significant differences were found in cycling (SS=1:14:46 ± 2:48 vs. WS=1:14:37 ± 2:54 min), running (SS=55:40 ± 1:49 vs. WS=57:20 ± 4:00 min) or total triathlon times (SS=2:40:26 ± 1:58 vs. WS=2:41:57 ± 1:37 min). Therefore, the primary finding was that wearing a wet suit during the swimming stage of an Olympic distance triathlon in 25.4°C water does not adversely affect the thermal responses or the triathlete's ability to perform on the subsequent cycling and running stages. / School of Physical Education

The purposes of the investigation were to determine and analyze the effects of dry heat upon the physical and mental performance tasks and to deduce implications for the improvement of educational practices.

This study has five chapters, organized in the following manner: (1) Chapter I contains the introduction, statement of the problem, purposes of the study, hypotheses, and significance of the study; (2) Chapter II is a review of the literature; (3) Chapter III is a description of subjects and tests and the procedures for treating the data; (4) Chapter IV contains the statistical technique of the analysis and the findings related to the hypotheses; and, (5) Chapter V consists of the summary, conclusions, and recommendations. The purpose of this study was to determine performance levels in the areas of (1) agility, (2) endurance, (3) reaction time, and (4) strength at high (ninety degrees Fahrenheit) and ideal (sixty-eight degrees Fahrenheit) environmental temperatures. On the basis of the findings it was concluded that (1) high temperature (ninety degrees Fahrenheit) causes human motor performance to deteriorate, and ideal temperature (sixty-eight degrees Fahrenheit) causes human motor performance to be improved; (2) the three components which showed a significant difference required more muscular action than did the component (reaction time) which showed no significant difference; (3) the majority of previous findings agree with the present research in respect to agility and reaction time; and (4) results were evenly divided as to the effects of heat on endurance and strength, with present research adding credence to improved performance in ideal temperature.

Typescript. / Digitized by Kansas Correctional Industries

Typescript. / Digitized by Kansas Correctional Industries